# Screen space reflection(water).I need help **URL:** \ **Category:** CesiumJS\ **Created:** [October 14, 2021, 6:09am UTC](https://community.cesium.com/t/screen-space-reflection-water-i-need-help/15692 "2021-10-14T06:09:25Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![linsanda](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/linsanda/32/6669_2.png) [@linsanda](https://community.cesium.com/u/linsanda)\ **Post date:** [October 14, 2021, 6:09am UTC](https://community.cesium.com/t/screen-space-reflection-water-i-need-help/15692/1 "2021-10-14T06:09:25Z")
[Demo](https://sandcastle.cesium.com/#c=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) ![water](https://global.discourse-cdn.com/cesium/original/2X/8/87071f97236c48058653cdf5d311daf04037519f.png) ---
**Author:** ![sam.rothstein](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/sam.rothstein/32/6584_2.png) [@sam.rothstein](https://community.cesium.com/u/sam.rothstein)\ **Post date:** [October 14, 2021, 7:54pm UTC](https://community.cesium.com/t/screen-space-reflection-water-i-need-help/15692/2 "2021-10-14T19:54:23Z")
@linsanda Thank you for sharing this with the community! I opened up your sandcastle demo and noticed some very odd behavior. It seems like parts of the terrain are appearing near the blue box entity that you added. Just so that I am clear - what is your goal with this project? -Sam ---
**Author:** ![linsanda](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/linsanda/32/6669_2.png) [@linsanda](https://community.cesium.com/u/linsanda)\ **Post date:** [October 14, 2021, 9:13pm UTC](https://community.cesium.com/t/screen-space-reflection-water-i-need-help/15692/3 "2021-10-14T21:13:17Z")
I want to achieve water reflection in post processing. I try to use Ray Marching in Eye Space.（I can only describe it briefly. My English is not very good） ---
**Author:** ![sam.rothstein](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/sam.rothstein/32/6584_2.png) [@sam.rothstein](https://community.cesium.com/u/sam.rothstein)\ **Post date:** [October 14, 2021, 10:08pm UTC](https://community.cesium.com/t/screen-space-reflection-water-i-need-help/15692/4 "2021-10-14T22:08:21Z")
@linsanda I do not think our API currently provides an easy way to implement water reflections in post-processing. I currently do not have a timeline for when this will be implemented. However, I did find this community forum thread that partially addresses this topic. > [@Water effects and animation](https://community.cesium.com/t/water-effects-and-animation/7725): > > Anxious, I would like to ask you, I want to use the geometry with water, but need to modify the shape of the geometry to make an animation, cesium has the way to use the entity to complete the water effect, or how to add animation to the PolygonGeometry. I hope to give me a method. Thank you. Here is my code     var Polygon1 = viewer.scene.primitives.add(new Cesium.Primitive({         geometryInstances : new Cesium.GeometryInstance({             geometry : new Cesium.PolygonGeometry({       … -Sam